A disciplinary hearing against four students who took part in student protests at the University of Sussex came to an end on Thursday, with the students being given a caution by their university.

A wave of student protests in 2013 against the privatisation of university services led to the suspension of the students. They were accused of "actively organising or leading unlawful occupations and associated events", according to John Duffy, registrar and secretary at the University of Sussex.

Following the verdict, the students will receive a warning letter from the university. It has taken several months for the University of Sussex to reach a decision on this issue. In January the hearing was postponed after claims that university deputy vice-chancellor Michael Davies was a biased chair of the hearing.

The students sought legal representation from prominent human rights barrister Geoffrey Robertson QC, who said: "Disciplining the students would set a very bad precedent for universities up and down the country, so that's what is at stake."

Over the past few months the students have received support via social media, with students tweeting using the hashtag #sackfarthing, to protest against the university vice chancellor Michael Farthing and the decision to put the students through a disciplinary hearing.

Simon Natas, a solicitor at ITN solicitors and one of the people representing the students, said: "'My clients faced allegations which were initially thought serious enough to justify their suspension and possibly even expulsion from their university but which have now resulted in a mere reprimand.

"We hope that lessons will be learned from these proceedings and that in the future, students will be free to engage in peaceful protest on campus without fear of disciplinary sanction."

Michael Segalov, one of the students who went through the trial, said: "I have maintained throughout that participating in peaceful protest action is something to be encouraged, and is not punishable. We intend to challenge this decision, which suggests we are guilty of wrongdoing, and are seeking advice on this."

The University of Sussex defended their decision, saying: "The university believes it has acted properly and correctly.

"Protests have repeatedly descended to violence, campus property has been damaged, the personal property of staff has been stolen and individual members of staff have faced intimidation. It was in this context that the university instigated internal disciplinary proceedings.

"A caution means that no immediate punishment is imposed, but the student is warned that if he or she were to be found guilty of another breach of discipline, the first breach should be taken into account and regarded as an aggravating circumstance when considering a sanction for the second offence."

• This article was amended on 14 March 2014 to include a comment from the University of Sussex who were previously unavailable to comment.